1. Field of the Invention
This invention relates to the handling of bales of hay, and more particularly concerns a device specially suited for the handling of spirally wound cylindrical bales of hay.
2. Description of the Prior Art
The use of spirally wound bales of hay has become very popular in recent years for various reasons. Such bales may typically have a diameter of about six feet and an axial length of about five feet. However, their large size and considerable weight, often 1500 to 2000 pounds, creates special problems in their handling and transportation. Handling devices have earlier been disclosed, but most are relatively complicated, requiring complex structure and operating features not useful for purposes other than bale handling. Other devices have been created which are attachments to tractors, trucks, or other farm vehicles. These attachment devices have been generally designed to impale and transport bales. Such devices generally must be attached to the farm vehicle prior to use, and removed before the vehicle is used for other purposes. Moreover, bale impaling devices are impractical for handling loosely bound bales and small square bales, and have limited ability to manipulate bales.
A front end loader, often referred to as a bucket loader, is a widely used piece of equipment found in many commercial and industrial applications such as construction and excavating operations, and agricultural applications, including farming and livestock activities. Bucket loaders are of various sizes and configurations, but basically include a prime mover, such as a tractor or the like, having a pair of pivotably supported lift arms that are hydraulically driven to raise or lower a bucket attached to the ends of the lift arms and disposed in front of the tractor. Hydraulic cylinders are generally used to pivot the bucket about a horizonatal axis so as to move the bucket from a load receiving to a load discharging position, and vise-versa. The primary use of a bucket loader is to transfer bulk materials such as sand, gravel, earth, manure, etc. For example, bucket loaders are used in livestock operations for scooping manure from livestock pens and loading same on a spreader, while in construction operations a bucket loader may typically be used to transfer earth from a pile into a dump truck.
Due to the large investment in a bucket loader, and for other reasons, it has been common practice to adapt bucket loaders to perform operations other than the transferring of bulk materials. This practice adds versatility to the loader and thereby eliminates the need and associated costs for using separate pieces of equipment or tools to perform separate operations. Several bucket-attached devices for handling hay bales have been earlier disclosed.
On such example of a handler for round bales in disclosed in U.S. Pat. No. 4,120,405, wherein accessory structure having three spear-shaped bale engaging prongs is attached to a front-end loader. However, emplacement of the accessory structure requires that the bucket be removed, permitting the accessory structure to be directly attached to the lift arms of the loader.
Another type of round bale handler is dislcosed in U.S. Pat. No. 3,921,837, wherein a pair of forks are attached by brackets to the sidewalls of the bucket.
Yet another round bale handler is described in U.S. Pat. No. 4,329,103, wherein the bale handling device must be removed to permit conventional use of the bucket loader.
The above described bucket loader conversion units or attachments all suffer various shortcomings. Although some prior conversion units have advantages over other ones and certain ones have specific disadvantages. It can be concluded that there exists a need for an improved bucket loader conversion attachment which does not interfere with normal functions of the bucket.
A common accessory to the bucket loader is the addition of a grapple having a multiplicity of forwardly disposed teeth downwardly directed from a framework which is pivotably connected to the top of the bucket structure. A hydraulic cylinder is typically used to pivot the grapple framework about a horizontal axis in order to embrace large objects such as hay bales or compactible materia such as loose hay. The grapple may be pivoted to an upward position so as not to interfere with the operation of the bucket when handling normal bulk materials which do not require embracing. One shortcoming of grapple assemblies is that an additional hydraulic piston unit is usually required to control the raising and lowering of the grapple. Such an additional piston requires additional hydraulic valves, hoses, control lever, and hydraulic pump capacity. The cost of such additional equipment can render the retrofitting of an existing front loader with a grapple economically unfeasible.
It is accordingly an object of the present invention to provide an improved grapple apparatus adapted to mount upon the lift arms of a front end loader.
It is another object of this invention to provide a device of the aforesaid nature which does not require additional hydraulic equipment to raise and lower the grapple.
It is a further object of the present invention to provide a device of the aforesaid nature specifically adapted to grip bales of hay, and which does not need to be removed from the bucket to permit other uses of the loader.
It is still another object of this invention to provide a device of the aforesaid nature which is easy to install and amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.